Imprint method, imprint apparatus, and article manufacturing method

ABSTRACT

Provided is an imprint method of performing an imprint process including a contacting step of bringing a mold into contact with an imprint material on a substrate, a curing step of curing the imprint material, and a separating step of separating the mold from the cured imprint material. The method includes acquiring global alignment information, performing a pre-alignment measurement including moving, based on the acquired global alignment information, a second shot region to a measurement position at which a measurement device performs measurement, and measuring a first relative positional shift between the second shot region and the mold using the measurement device, and moving, based on the global alignment information and the measured first relative positional shift, a first shot region to an imprint position at which the imprint process is performed, and starting the contacting step.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to an imprint method, an imprintapparatus, and an article manufacturing method.

Description of the Related Art

An imprint apparatus is beginning to be put into practical use as onelithography technique for mass-production of magnetic storage media orsemiconductor devices. The imprint apparatus brings a mold with a finecircuit pattern formed into contact with an imprint material on asubstrate such as a silicon wafer or glass plate, thereby forming apattern on the substrate.

For example, in forming a circuit pattern of a semiconductor device, theoverlay accuracy between a circuit pattern already formed on a substrateand a circuit pattern to be formed can be very important. As analignment method in an imprint apparatus, global alignment anddie-by-die alignment can be adopted. The global alignment is a method ofestimating the positions of all shot regions based on the measurementresults of marks in a plurality of sample shot regions on a substrate.The die-by-die alignment is a method of correcting a positional shiftbetween a substrate and a mold by optically detecting a substrate-sidemark and a mold-side mark for each shot region.

Japanese Patent Laid-Open No. 2016-076626 describes that coarsealignment (pre-alignment) can be performed after global alignment andbefore die-by-die alignment. Japanese Patent Laid-Open No. 2012-084732describes that, as pre-alignment, a mark on a mold and a mark on a waferare detected in a state in which the mold and a resin applied onto thewafer are not in contact with each other.

Before bringing a mold into contact with an imprint material on a shotregion, pre-alignment is performed in the first shot region to beimprinted or every time imprinting is performed. By performingpre-alignment, it is possible to decrease an initial relative positionalshift when bringing the mold into contact with the imprint material onthe shot region.

However, if an imprint target shot region is a peripheral shot regionlocated in the periphery of the substrate, the overlay accuracy maydegrade due to restrictions on the arrangement of marks or a factor thatmarks are not normally formed by a process in a previous step.

To implement formation of an accurate multilayer circuit pattern,improvement of the overlay accuracy in the imprint technique is animportant requirement.

SUMMARY OF THE INVENTION

The present invention provides, for example, an imprint methodadvantageous in terms of overlay accuracy.

The present invention in its one aspect provides an imprint method ofperforming an imprint process including a contacting step of bringing amold into contact with an imprint material supplied onto a substrate, acuring step of curing the imprint material in a state in which theimprint material and the mold are in contact with each other, and aseparating step of separating the mold from the cured imprint material.The method comprises acquiring global alignment information includinginformation for specifying position coordinates of each of a pluralityof shot regions including a first shot region and a second shot regionof the substrate, performing a pre-alignment measurement includingmoving, based on the acquired global alignment information, the secondshot region to a measurement position at which a measurement deviceperforms measurement, and measuring a first relative positional shiftbetween the second shot region and the mold using the measurementdevice, and moving, based on the global alignment information and themeasured first relative positional shift, the first shot region to animprint position at which the imprint process is performed, and startingthe contacting step.

Further features of the present invention will become apparent from thefollowing description of exemplary embodiments (with reference to theattached drawings).

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view showing the arrangement of an imprint apparatus;

FIG. 2 is a flowchart of an imprint process;

FIGS. 3A to 3C are views for explaining the imprint process;

FIG. 4 is a view exemplifying an imprinting order of a plurality of shotregions of a substrate;

FIG. 5 is a view showing an example of classification of peripheral shotregions and full shot regions;

FIG. 6 is a view showing examples of the mark arrangements of theperipheral shot region and the full shot region;

FIG. 7 is a flowchart of the imprint process;

FIG. 8 is a flowchart of the imprint process;

FIG. 9 is a view for explaining a conventional imprint process by MFD;

FIG. 10 is a view for explaining an imprint process by MFD;

FIG. 11 is a view for explaining measurement of a pre-alignment shotduring global alignment; and

FIG. 12 is a view for explaining an article manufacturing methodaccording to an embodiment.

DESCRIPTION OF THE EMBODIMENTS

Hereinafter, embodiments will be described in detail with reference tothe attached drawings. Note, the following embodiments are not intendedto limit the scope of the claimed invention. Multiple features aredescribed in the embodiments, but limitation is not made to an inventionthat requires all such features, and multiple such features may becombined as appropriate. Furthermore, in the attached drawings, the samereference numerals are given to the same or similar configurations, andredundant description thereof is omitted.

First Embodiment

FIG. 1 is a view showing the arrangement of an imprint apparatus 100according to an embodiment. In this specification and the attacheddrawings, directions are indicated in an XYZ-coordinate system where thehorizontal plane as an XY plane. Generally, a substrate W, which is theobject on which a pattern is formed, is placed on a substrate stage 104so that the surface of the substrate W is parallel to the horizontalplane (XY plane). Therefore, in the following, the directions orthogonalto each other in the plane along the surface of the substrate W aredefined as the X-axis and the Y-axis, and the direction orthogonal tothe X-axis and the Y-axis is defined as the Z-axis. Further, in thefollowing, the directions parallel to the X-axis, Y-axis, and Z-axis inthe XYZ coordinate system are referred to as an X-direction, aY-direction, and a Z-direction, respectively, and the rotation directionaround the X-axis, the rotation direction around the Y-axis, and therotation direction around the Z-axis are referred to as a θx direction,a θy direction, and a Oz direction, respectively.

Firstly, an overview of an imprint apparatus according to an embodimentwill be described. The imprint apparatus is an apparatus that brings animprint material supplied onto a substrate into contact with a mold andsupplies curing energy to the imprint material to form a pattern of thecured material to which a concave-convex pattern of the mold istransferred.

As an imprint material, a curable composition (to be sometimes called anuncured resin) that is cured upon application of curing energy is used.As curing energy, electromagnetic waves, heat, or the like can be used.Electromagnetic waves can be, for example, light selected from thewavelength range of 10 nm or more and 1 mm or less, for example,infrared light, visible light, or ultraviolet light, or the like. Acurable composition can be a composition that is cured by beingirradiated with light or by being heated. Of these compositions, aphoto-curable composition that is cured by being irradiated with lightcontains at least a polymerizable compound and a photopolymerizationinitiator, and may further contain a non-polymerizable compound or asolvent, as needed. A non-polymerizable compound is at least one type ofcompound selected from the group consisting of a sensitizer, hydrogendonor, internal mold release agent, surfactant, antioxidant, and polymercomponent. An imprint material supply apparatus can arrange an imprintmaterial on a substrate in the form of droplets or islands or filmsformed from a plurality of droplets connected to each other. Theviscosity (the viscosity at 25° C.) of the imprint material can be, forexample, 1 mPa s or more and 100 mPa s or less. As a material for asubstrate, for example, glass, ceramic, metal, semiconductor, or resincan be used. The surface of a substrate may be provided with a membermade of a material different from that of the substrate, as needed. Forexample, a silicon wafer, a compound semiconductor wafer, silica glass,or the like is used as the substrate.

Referring to FIG. 1 , the imprint apparatus 100 includes a curing device102, a mold holder 103, the substrate stage 104, a supply device 105, acontroller 107, a TTM measurement device 122, and an off-axismeasurement device 131.

The curing device 102 emits light 109 (ultraviolet light) for curing animprint material in a state in which a mold 108 and the imprint materialon a substrate are in contact with each other. The curing device 102 caninclude a light source (not shown) and an optical element that adjuststhe light 109 emitted from the light source to light suitable forimprinting. The imprint material on the substrate is irradiated with theemitted light 109 having passed through the mold 108. Note that in thisembodiment, a photocuring method is adopted and thus the curing device102 is configured to emit the light 109. If, however, a thermal curingmethod is adopted, the curing device 102 includes a heat source unit forcuring an imprint material made of a thermosetting composition.

The mold 108 includes a pattern portion 8 a three-dimensionally formedon the first surface facing a substrate 111. In the pattern portion 8 a,for example, a concave-convex pattern such as a circuit pattern to betransferred to the substrate is formed. The mold 108 is made of amaterial such as quartz that can transmit the light 109. The mold 108can have a shape including, on the opposite side of the first surface, acavity (concave portion) 8 b that makes it easy to deform the mold 108in the Z direction. For example, the cavity 8 b has a circular planarshape when viewed from the Z direction, and has a thickness (depth) thatis set in accordance with the size and the material of the mold 108.Alternatively, in an opening region 117 in the mold holder 103, a lighttransmitting member 113 that sets, as a closed space, a space 112surrounded by part of the opening region 117 and the cavity 8 b can bearranged, and a pressure regulation device (not shown) can control thepressure in the space 112. For example, when bringing the mold 108 intocontact with an imprint material 114 on the substrate 111, the pressureregulation device warps the pattern portion 8 a into a convex shapetoward the substrate 111 by setting the pressure in the space 112 to behigher than that in an external space. This can bring the pattern region8 a into contact with the imprint material 114 from the center of thepattern region 8 a. After that, by gradually decreasing the pressure inthe space 112, the contact advances from the center of the patternportion 8 a to the peripheral portion. This prevents gas from beingtrapped between the pattern portion 8 a and the imprint material 114,thereby making it possible to fill the entire concave-convex portion ofthe pattern region 8 a with the imprint material 114.

The mold holder 103 also called an imprint head includes a mold chuck115 that holds the mold 108 by attracting it by a vacuum suction forceor an electrostatic force, and a mold driver 116 that moves the moldchuck 115 (that is, the mold 108). The mold chuck 115 and the molddriver 116 have the opening region 117 in the center so that the light109 emitted from the light source of the curing device 102 is emitted tothe substrate 111.

The mold holder 103 further includes a shape correction unit 118 forcorrecting the shape of the mold 108 (pattern portion 8 a) by applyingan external force to a plurality of portions on the side surface of themold 108. The shape correction unit 118 can deform the shape of the mold108 in accordance with the shape of the pattern already formed on thesubstrate 111.

The mold driver 116 moves the mold 108 in the Z direction so as toselectively bring the mold 108 into contact with the imprint material114 on the substrate 111 or separate (release) the mold 108 from theimprint material 114 on the substrate 111. Examples of an actuator thatcan be adopted for the mold driver 116 are a linear motor and an aircylinder. To cope with accurate positioning of the mold 108, the molddriver 116 may include a plurality of driving systems such as a coarsedriving system and a fine driving system. Furthermore, the mold driver116 may have a position adjustment function not only in the Z directionbut also in the X direction, the Y direction, or the Oz direction, atilt function of correcting the tilt of the mold 108, and the like. Notethat the contact and releasing operations in the imprint apparatus 100may be implemented by moving the mold 108 in the Z-axis direction, asdescribed above, but may be implemented by moving the substrate stage104 in the Z-axis direction or by moving both the mold 108 and thesubstrate stage 104 relatively.

The substrate stage 104 moves while holding the substrate 111. Thesubstrate stage 104 includes a substrate chuck 119 (substrate holder)that holds the substrate 111 by a suction force and a stage driver 120that holds the substrate chuck 119 to be movable in the X-Y plane. Thesubstrate chuck 119 can include a plurality of suction portions (notshown) that suck and hold the lower surface of the substrate 111 by aplurality of regions. These suction portions are connected to a pressureregulation device different from the above-described one. Each pressureregulation device generates a suction force by regulating the pressurebetween the substrate 111 and each suction portion, thereby holding thesubstrate 111 on the chucking surface. At this time, it is possible tochange the pressure value (suction force) individually for each suctionportion. Note that the division number of suction portions (the numberof arranged suction portions) is not particularly limited, and anarbitrary number is possible. Furthermore, the substrate stage 104includes a reference mark 121 to be used to align the mold 108 on thesurface of the substrate stage 104. The stage driver 120 can adopt, forexample, a linear motor as an actuator. The stage driver 120 may includea plurality of driving systems such as a coarse driving system and afine driving system in each of the X and Y directions. The stage driver120 may also have a driving system for position adjustment in the Zdirection, a position adjustment function of the substrate 111 in the 0direction, or a tilt function of correcting the tilt of the substrate111. By driving the substrate stage 104, the substrate 111 can bealigned with respect to the mold 108.

The supply device 105 supplies (arranges) the imprint material onto thesubstrate 111. The supply device 105 includes a discharge nozzle thatdischarges the imprint material. The amount of the imprint materialdischarged from the discharge nozzle is decided appropriately based on adesired thickness of the imprint material 114 to be formed on thesubstrate 111 and the density of a pattern to be formed.

The TTM measurement device 122 is arranged in, for example, the openingregion 117, and includes a scope that includes an optical system and animaging system to measure a positional shift in the X and Y directionsbetween an alignment mark formed on the substrate 111 and that formed onthe mold 108. Note that “TTM” is an abbreviation for “Through The Mold”,and is intended to observe the mold-side mark and the substrate-sidemark via the mold.

On the other hand, the off-axis measurement device 131 includes a scopethat includes an optical system and an imaging system to detect thealignment mark formed on the substrate 111 without intervention of themold 108. The use of the TTM measurement device 122 and the off-axismeasurement device 131 makes it possible to relative alignment betweenthe mold 108 and the substrate 111.

Furthermore, the imprint apparatus 100 includes a base surface plate 124on which the substrate stage 104 is placed, a bridge surface plate 125that fixes the mold holder 103, and columns 126 that are extended fromthe base surface plate 124 to support the bridge surface plate 125. Theimprint apparatus 100 also includes a mold conveyance mechanism (notshown) that conveys the mold 108 from the outside of the apparatus tothe mold holder 103, and a substrate conveyance mechanism (not shown)that conveys the substrate 111 from the outside of the apparatus to thesubstrate stage 104.

The controller 107 can control the operation, adjustment, and the likeof each constituent element of the imprint apparatus 100. The controller107 can be configured as, for example, a computer including a processor(CPU) and a memory, and can be connected to each constituent element ofthe imprint apparatus 100 via a line to control each constituent elementin accordance with a program. Note that the controller 107 may be formedintegrally (in a common housing) with the other parts of the imprintapparatus 100 or may be formed separately (in another housing) from theother parts of the imprint apparatus 100.

[Overview of Imprint Process]

An imprint process (imprint method) of forming a pattern on thesubstrate by bring the mold 108 into contact with the imprint material114 on the substrate will be described with reference to FIGS. 2 and 3Ato 3C. In step S300, the controller 107 controls the mold conveyancemechanism to convey the mold 108 designated by the lot from a moldstocker to the mold holder 103, and fixes the mold 108 to the mold chuck115. In step S302, the controller 107 controls the substrate conveyancemechanism to convey the substrate 111 as a processing target from asubstrate carrier to the substrate stage 104, and fixes the substrate111 to the substrate chuck 119.

Next, the controller 107 performs pre-alignment measurement to measurethe relative position between the mold 108 and each shot in thesubstrate 111.

In step S304, the controller 107 causes the TTM measurement device 122to observe a mold-side mark 63 on the mold 108 and measure its position.Subsequently, the controller 107 causes the TTM measurement device 122to observe a mark (not shown) on the substrate stage 104 and measure theposition of the substrate stage 104 with respect to the TTM measurementdevice 122.

In step S306, global alignment measurement is performed. In the globalalignment measurement, the controller 107 drives the substrate stage 104so that the substrate 111 is located at a position under the off-axismeasurement device 131. After that, the controller 107 uses the off-axismeasurement device 131 to measure the positional shifts of marks in aplurality of sample shot regions in the substrate 111 with reference tothe substrate stage 104. The positional shift indicates the positionalshift of a mark with respect to the measurement position of the off-axismeasurement device 131, which is detected when driving, based on designdata of a shot array, the substrate stage 104 so that the mark in eachsample shot region is located at the measurement position. After that,the controller 107 performs statistical processing such as functionfitting and abnormal value processing based on the obtained positionalshift in each sample shot region. By performing this statisticalprocessing, global alignment information including information of thepositional relationship among the plurality of shot regions to specifythe position coordinates of all the shot regions on the substrate 111 isacquired.

The controller 107 designates a shot region that has not been imprintedyet. A region (processed region) to be imprinted in the substrate willbe referred to as a “shot region (or simply, shot)” hereinafter. Animprinting order can be, for example, an order of shot 1, shot 2, shot3, shot 4, . . . , shot 6, shot 7, shot 8, . . . , shot 14, . . . ascontinuous shot regions on the substrate 111, as shown in FIG. 4 . Theimprinting order is not limited to this, and an order such as astaggered order or random order can be set. However, the imprintingorder of sequentially imprinting the shot regions adjacent to eachother, as shown in FIG. 4 , is a typical example advantageous in termsof throughput. The shot layout and the imprinting order are saved inadvance as a recipe in a memory or the like of the controller 107.

To align the substrate and the mold more accurately, pre-alignmentmeasurement is executed in step S308. The pre-alignment measurement isperformed as follows. Based on the global alignment information acquiredin step S306, the controller 107 controls the substrate stage 104 sothat the shot region to be imprinted first is located at a measurementposition corresponding to an imprint position under the pattern portion8 a of the mold 108. After that, as shown in FIG. 3A, the controller 107simultaneously observes a substrate-side mark 62 and the mold-side mark63 using the TTM measurement device 122, and measures the relativepositional shift between them.

In step S310, the controller 107 controls the substrate stage 104 sothat the target shot region (the shot region to undergo the imprintprocess) is located at a supply position under the supply device 105,and the supply device 105 supplies the imprint material 114 to thetarget shot region.

Step S312 is a contact step. In the contact step, the controller 107first controls the substrate stage 104 so that the target shot region islocated at a position (imprint position) under the mold holder 103. Atthis time, the controller 107 drives the substrate stage 104 based onthe global alignment information acquired in step S306 and the relativepositional shift obtained by the pre-alignment measurement in step S308.After that, the controller 107 controls the mold holder 103 to drive themold 108 in the Z direction, thereby bringing the pattern portion 8 a ofthe mold 108 into contact with the imprint material 114 on the targetshot region. To prevent bubbles from being generated, the pressure inthe space 112 is regulated at the time of contact, as described above.As shown in FIG. 3B, the contact makes the imprint material 114 flowalong the concave-convex pattern formed in the pattern portion 8 a, anda portion between the substrate 111 and the pattern portion 8 a isfilled with the imprint material 114.

In step S314, the controller 107 measures the relative positional shiftbetween the substrate-side mark 62 and the mold-side mark 63 using theTTM measurement device 122, and controls the substrate stage 104 and theshape correction unit 118 so that the relative positional shift amountfalls within a predetermined tolerance. Thus, the pattern portion 8 a ofthe mold 108 and the target shot region are aligned. This alignment isperformed for each shot region, and is called die-by-die alignment.

In step S316, in a state in which the mold 108 and the imprint material114 are in contact with each other, the controller 107 causes the curingdevice 102 to emit the light 109 to cure the imprint material (curingstep). After the imprint material 114 is cured, the controller 107controls, in step S318, the mold holder 103 to separate the mold 108from the cured imprint material 114 (releasing step), as shown in FIG.3C.

In step S320, the controller 107 determines whether there is a shotregion to be processed next. If there is a shot region to be processednext, the process returns to step S310, and the imprint process of thenext shot region is performed. In the imprint process of the next shotregion, the shot region is moved from the supply position of the imprintmaterial to a position under the mold holder 103 for the contact step instep S312. At this time as well, the substrate stage 104 is driven basedon the global alignment information acquired in step S306 and therelative positional shift obtained by the pre-alignment measurement instep S308. If it is determined in step S320 that there is no shot regionto be processed next, the process advances to step S322. In this way,the imprint process is performed for all the shot regions designated bythe lot, thereby forming the pattern on the entire surface of thesubstrate 111.

In step S322, the controller 107 controls the substrate conveyancemechanism to collect the substrate 111 placed on the substrate chuck 119and having undergone the imprint process. In step S324, the controller107 determines whether there is a substrate to be processed next. Ifthere is a substrate to be processed next, the process returns to stepS302, and the imprint process is performed for the next substrate. Ifthere is no substrate to be processed next, the process shifts to stepS326. In step S326, the controller 107 controls the mold conveyancemechanism to collect the mold 108 held by the mold chuck 115.

[Improvement of Pre-Alignment Measurement]

The die-by-die alignment executed in step S314 aligns the target shotregion and the pattern portion 8 a of the mold 108. Since, during thedie-by-die alignment, the mold 108 is in contact with the imprintmaterial 114 on the substrate 111, an alignment amount is limited, andit takes time to perform alignment. Therefore, it is necessary todecrease the alignment amount between the substrate 111 and the mold 108during the die-by-die alignment. The pre-alignment measurement in stepS308 performed before bringing the mold 108 into contact with theimprint material 114 on the substrate 111 influences the alignmentamount between the substrate 111 and the mold 108 during the die-by-diealignment. Improved pre-alignment measurement will be described below.

As described above, in the example shown in FIG. 4 , the continuous shotregions shot 1, shot 2, shot 3, shot 4, . . . , shot 6, shot 7, shot 8,. . . , shot 14, . . . on the substrate 111 are imprinted in this order.These shot regions include “peripheral shot regions” located in theperipheral portion of the substrate 111. The peripheral shot regions arealso called partial fields (PFs). Shot regions other than the peripheralshot regions are called full shot regions or full fields (FFs). Tomaximize the effective area (the area of a region to which the patternis transferred) of the substrate 111, the imprint process can also beperformed for the peripheral shot regions.

FIG. 5 is a view showing an example of classification of the peripheralshot regions (PFs) and the full shot regions (FFs). Each “peripheralshot region” typically includes a “partial shot region” where part ofthe pattern portion 8 a of the mold 108 partially protrudes from theperipheral portion (periphery) of the substrate 111 when bringing themold 108 into contact with the imprint material on the substrate 111 andonly part of the pattern portion 8 a is transferred. A shot region thathas no “omission” but has a corner only contacting the peripheralportion of the substrate or a shot region at a position near theperipheral portion of the substrate can be classified as a peripheralshot region. For example, since a region a predetermined distance (forexample, 3 mm) away from the periphery of the substrate is readilyinfluenced by a process in a previous step, it can be regarded as aninvalid area that is not targeted by the imprint process. A shot regionpartially overlapping the invalid area may also be classified as aperipheral shot region.

As shown in FIG. 6 , the PF is smaller in area than the FF, and is thusrestricted in terms of the degree of freedom of the arrangement ofmarks, as compared with the FF. For example, while marks (AM131, AM132,AM133, and AM134) can be arranged at four corners in the FF, at mostthree marks (AM011, AM012, and AM013) can be arranged at a narrowinterval in the PF. Therefore, in the PF, the averaging effect whencalculating translation components by performing statistical processingfor each mark becomes small, thereby degrading the accuracy. In the PF,since the arrangement of the marks (the distance between the marks) isrestricted, the span between the mark and the scope also becomes short.This may increase a correction error of a rotation component or thelike. In addition, the possibility that a mark is not normally formed bythe process in the previous step is higher in the PF than in the FF. Forexample, the mark AM013 is located near the invalid area in theperiphery of the substrate. The mark at this position may not be formednormally. If pre-alignment measurement is performed using the mark notformed normally, the alignment accuracy degrades, thereby increasing thealignment amount during the die-by-die alignment.

In this embodiment, not the target shot region but the FF geometricallynearest to the target shot region is used as the shot region for whichthe pre-alignment measurement in step S308 is executed. In the exampleshown in FIG. 4 , shot 1 (the first shot region) that is imprinted firstis the PF. According to this embodiment, if shot 1 is the target shotregion, not shot 1 but shot 13 (second shot region) as the FFgeometrically nearest to shot 1 is selected as the shot region for whichthe pre-alignment measurement in step S308 is executed. Thegeometrically nearest shot region indicates, for example, a shot regionhaving a shortest distance between shot centers. Note that therelationship between the first shot region and the second shot region isnot always limited to the relationship between the PF and the FF, andmay be a relationship that can sufficiently obtain the effect in termsof the productivity and the accuracy of the pre-alignment measurement.

FIG. 7 is a flowchart of the imprint process according to thisembodiment. This flowchart is mostly the same as that shown in FIG. 2except that step S308′ is executed as pre-alignment measurement insteadof step S308. In step S308′, pre-alignment measurement is performed fora shot region different from the target shot region. For example, asdescribed above, if shot 1 is the target shot region, the pre-alignmentmeasurement is performed for not shot 1 but shot 13 as the FFgeometrically nearest to shot 1. More specifically, based on the globalalignment information acquired in step S306, the controller 107 controlsthe substrate stage 104 so that shot 13 is located at a measurementposition corresponding to an imprint position under the pattern portion8 a of the mold 108. After that, the controller 107 simultaneouslyobserves the substrate-side mark 62 and the mold-side mark 63 using theTTM measurement device 122, and measures the relative positional shiftbetween them.

Then, in step S310, the controller 107 controls the substrate stage 104so that shot 1 as the target shot region is located at the supplyposition under the supply device 105, and the supply device 105 suppliesthe imprint material 114 to shot 1. In step S312, the controller 107controls the substrate stage 104 so that shot 1 is located at theposition (imprint position) under the mold holder 103. At this time, thecontroller 107 drives the substrate stage 104 based on the globalalignment information acquired in step S306 and the result obtained bythe pre-alignment measurement (that is, the pre-alignment measurementfor shot 13) in step S308′.

After that, the controller 107 controls the mold holder 103 to drive themold 108 in the Z direction, thereby bringing the pattern portion 8 a ofthe mold 108 into contact with the imprint material 114 on shot 1 as thetarget shot region. In the imprint process of shot 2 and subsequent shotregions as well, the substrate stage 104 is driven based on the globalalignment information acquired in step S306 and the result obtained bythe pre-alignment measurement for shot 13 in step S308′.

The above-described example has explained that the substrate stage isdriven to the next shot position based on the pre-alignment measurementresult of shot 13. The present invention, however, is not limited tothis. For example, the target position of the substrate stage may becorrected based on the measurement value of the TTM measurement device122 during the die-by-die alignment in addition to the pre-alignmentmeasurement result. More specifically, the substrate stage 104 is drivenusing, as a correction amount, the positional shift measurement value atthe start of the die-by-die alignment. Furthermore, after imprinting aplurality of shot regions, statistical processing may be performed forthe positional shift measurement value at the start of the die-by-diealignment, and the position of the substrate stage may then be correctedbased on the result of the statistical processing. This can furtherdecrease the alignment amount during the die-by-die alignment.

As described above, according to this embodiment, if the target shotregion is restricted in terms of the arrangement of the marks and theformation accuracy like the PF, pre-alignment measurement is executedfor the FF (for example, shot 13) near the target shot region.Therefore, this is hardly influenced by the restrictions on thearrangement of the substrate-side mark 62 measured by the TTMmeasurement device 122 or the problem that the substrate-side mark 62 isnot formed normally by the process in the previous step. As a result,the alignment amount between the substrate 111 and the mold 108 in thedie-by-die alignment can be made small.

Note that this embodiment has explained a case in which pre-alignmentmeasurement is executed only for shot 1 as the first target shot region.However, pre-alignment measurement may be executed for each shot regionor executed at an interval of a predetermined number of shot regions,which is equal to or larger than two and is smaller than the totalnumber of shot regions, for example, when the column or row of the shotregion is changed. If pre-alignment measurement is executed for eachshot region, it is executed before supplying the imprint material to thetarget shot region, and after supplying the imprint material, thesubstrate stage is driven based on the pre-alignment measurement result.At this time, if the target shot region is the PF, the shot region (FF)which has not been imprinted and is geometrically nearest to the targetshot region is selected as a shot region for pre-alignment measurement.The same applies to a case in which pre-alignment measurement isexecuted at an interval of the number of shot regions, which is equal toor larger than two and is smaller than the total number of shot regions.

Furthermore, an imprint material discharge method different from theinkjet method may be used and the above-described imprint process may beexecuted for a substrate on which the imprint material has beenarranged. In this case, the imprint material supply step in step S310 ofFIG. 7 is eliminated, and step S312 is executed immediately after thepre-alignment measurement in step S308′.

(Modification)

FIG. 8 is a flowchart according to a modification of FIG. 7 . Referringto FIG. 8 , upon completion of the global alignment in step S306, thecontroller 107 determines, in step S307, with reference to, for example,the shot layout stored as a recipe in the memory, whether the targetshot region is the PF. Alternatively, the recipe may include in advance,for each shot region, information indicating whether the shot region isthe FF or PF. If the target shot region is the PF, the process shifts tostep S308′, as in FIG. 7 , and the pre-alignment measurement isperformed for the FF that is different from the target shot region andis near the target shot region. On the other hand, if the target shotregion is not the PF but the FF, it is unnecessary to use information ofanother shot region, and thus the process shifts to step S308, as inFIG. 2 , to perform the pre-alignment measurement for the target shotregion.

As described above, according to this embodiment, it is possible todecrease the alignment amount during the die-by-die alignment. Even ifthe imprint process is repeatedly performed, it is possible to form thepattern while satisfactorily maintaining the overlay accuracy withoutdecreasing the productivity.

Second Embodiment

The first embodiment has described the imprint process as SFD (SingleField Dispense). However, this embodiment performs an imprint process byMFD (Multi Field Dispense). In SFD, as described in the firstembodiment, a sequence of supply of the imprint material, contact,curing, and releasing is performed for each shot region. To thecontrary, in MFD, an imprint material is successively supplied to two ormore shot regions, and then a sequence of contact, curing, and releasingis performed for each of the shot regions to which the imprint materialhas been supplied. Since the driving amount of the substrate stage issmaller in MFD than in SFD that performs an operation of supplying theimprint material to each shot region, it is possible to improve theproductivity. FIG. 9 shows an example of the imprint process when MFD isperformed. In MFD, the imprint material is successively supplied to twoor more shot regions, and then contact and curing are performed for eachshot region. Therefore, exposure light for curing may influence theimprint material arranged in an adjacent shot region. To relax theinfluence, contact, curing, and releasing are performed for every othershot region in the example shown in FIG. 9 .

A conventional imprint process by MFD will be described first. In theconventional imprint process, pre-alignment measurement is performed forshot 1 (first pre-alignment shot) as the first target shot region in theshot region row. With respect to shot 1, a TTM measurement device 122 isused to simultaneously observe a substrate-side mark 62 and a mold-sidemark 63, and measure a positional shift. After the measurement, asubstrate stage 104 moves to a position under a supply device 105. Afterthat, a controller 107 controls the substrate stage 104 and the supplydevice 105 to successively supply an imprint material 114 to shot 1,shot 2, and shot 3 as every other shot regions on a substrate 111. Next,the substrate stage 104 is driven to arrange shot 1, to which theimprint material 114 has been supplied, at a predetermined position(imprint position) under a mold holder 103. At this time, the substratestage 104 is driven based on global alignment information and the resultof pre-alignment measurement for shot 1. The mold holder 103 drives amold 108 in the Z direction to bring a pattern portion 8 a of the mold108 into contact with the imprint material 114 on shot 1, therebyperforming die-by-die alignment. After that, the imprint material 114 iscured and released, thereby ending the imprint process for shot 1.

Subsequently, the substrate stage 104 is driven to arrange shot 2 at theimprint position under the mold holder 103. At this time, the substratestage 104 is driven based on the global alignment information and theresult of the pre-alignment measurement for shot 1. After that,die-by-die alignment, curing, and releasing are performed, therebyending the imprint process for shot 2. The imprint process is alsoexecuted for shot 3 in the same manner.

After that, pre-alignment measurement is executed again for shot 4(second pre-alignment shot) between shot 1 and shot 2. With respect toshot 4, the TTM measurement device 122 is used to simultaneously observethe substrate-side mark 62 and the mold-side mark 63, and measure apositional shift. After the measurement, the substrate stage 104 movesto a position under the supply device 105. After that, the controller107 controls the substrate stage 104 and the supply device 105 tosuccessively supply the imprint material 114 to shot 4, shot 5, and shot6 as every other shot regions on the substrate 111. Next, the substratestage 104 is driven to arrange shot 4, to which the imprint material 114has been supplied, at the imprint position under the mold holder 103. Atthis time, the substrate stage 104 is driven based on the globalalignment information and the result of the pre-alignment measurementfor shot 4. The mold holder 103 drives the mold 108 in the Z directionto bring the pattern portion 8 a of the mold 108 into contact with theimprint material 114 on shot 4, thereby performing die-by-die alignment.After that, the imprint material 114 is cured and released, therebyending the imprint process for shot 4.

Subsequently, the substrate stage 104 is driven to arrange shot 5 at theimprint position under the mold holder 103. At this time, the substratestage 104 is driven based on the global alignment information and theresult of the pre-alignment measurement for shot 4. After that,die-by-die alignment, curing, and releasing are performed, therebyending the imprint process for shot 5. The imprint process is alsoexecuted for shot 6 in the same manner.

Then, every time a new shot region row starts, pre-alignment isperformed for the first pre-alignment shot and the second pre-alignmentshot. In this conventional example, since pre-alignment is performed fora PF, the accuracy of the pre-alignment may degrade.

An imprint process by MFD according to this embodiment will be describednext with reference to FIG. 10 . In the imprint process according tothis embodiment, the first pre-alignment is performed for shot 2. Withrespect to shot 2, the TTM measurement device 122 is used tosimultaneously observe the substrate-side mark 62 and the mold-side mark63, and measure a positional shift. After the measurement, the substratestage 104 moves to a position under the supply device 105. After that,the controller 107 controls the substrate stage 104 and the supplydevice 105 to successively supply the imprint material 114 to shot 1,shot 2, and shot 3 as every other shot regions on the substrate 111.Next, the substrate stage 104 is driven to arrange shot 1, to which theimprint material 114 has been supplied, at the imprint position underthe mold holder 103. At this time, the substrate stage 104 is drivenbased on global alignment information and the result of thepre-alignment measurement for shot 2. The mold holder 103 drives themold 108 in the Z direction to bring the pattern portion 8 a of the mold108 into contact with the imprint material 114 on shot 1, therebyperforming die-by-die alignment. After that, the imprint material 114 iscured and released, thereby ending the imprint process for shot 1.

Subsequently, the substrate stage 104 is driven to arrange shot 2 at theimprint position under the mold holder 103. At this time, the substratestage 104 is driven based on the global alignment information and theresult of the pre-alignment measurement for shot 2. After that,die-by-die alignment, curing, and releasing are performed, therebyending the imprint process for shot 2. The imprint process is alsoexecuted for shot 3 in the same manner.

After that, pre-alignment measurement is executed again for shot 5 asthe second pre-alignment shot. With respect to shot 5, the TTMmeasurement device 122 is used to simultaneously observe thesubstrate-side mark 62 and the mold-side mark 63, and a positional shiftis measured. After the measurement, the substrate stage 104 moves to theposition under the supply device 105. After that, the controller 107controls the substrate stage 104 and the supply device 105 tosuccessively supply the imprint material 114 to shot 4, shot 5, and shot6 as every other shot regions on the substrate 111. Next, the substratestage 104 is driven to arrange shot 4, to which the imprint material 114has been supplied, at the imprint position under the mold holder 103. Atthis time, the substrate stage 104 is driven based on the globalalignment information and the result of the pre-alignment measurementfor shot 5. The mold holder 103 drives the mold 108 in the Z directionto bring the pattern portion 8 a of the mold 108 into contact with theimprint material 114 on shot 4, thereby performing die-by-die alignment.After that, the imprint material 114 is cured and released, therebyending the imprint process for shot 4.

Subsequently, the substrate stage 104 is driven to arrange shot 5 at theimprint position under the mold holder 103. At this time, the substratestage 104 is driven based on the global alignment information and theresult of the pre-alignment measurement for shot 5. After that,die-by-die alignment, curing, and releasing are performed, therebyending the imprint process for shot 5. The imprint process is alsoexecuted for shot 6 in the same manner.

Subsequently, a new shot region row starts, and pre-alignmentmeasurement is performed for shot 11 as the first pre-alignment shot.After a positional shift is measured with respect to shot 11, thesubstrate stage 104 moves to the position under the supply device 105.After that, the controller 107 controls the substrate stage 104 and thesupply device 105 to successively supply the imprint material 114 toshot 7, shot 8, shot 9, and shot 10 as every other shot regions on thesubstrate 111. Next, the substrate stage 104 is driven to arrange shot7, to which the imprint material 114 has been supplied, at the imprintposition under the mold holder 103. At this time, the substrate stage104 is driven based on the global alignment information and the resultof the pre-alignment measurement for shot 11. The mold holder 103 drivesthe mold 108 in the Z direction to bring the pattern portion 8 a of themold 108 into contact with the imprint material 114 on shot 7, therebyperforming die-by-die alignment. After that, the imprint material 114 iscured and released, thereby ending the imprint process for shot 7.

Subsequently, the substrate stage 104 is driven to arrange shot 8 at theimprint position under the mold holder 103. At this time, the substratestage 104 is driven based on the global alignment information and theresult of the pre-alignment measurement for shot 11. After that,die-by-die alignment, curing, and releasing are performed, therebyending the imprint process for shot 8. The imprint process is alsoexecuted for each of shot 9 and shot 10 in the same manner.

Subsequently, pre-alignment measurement is executed again for shot 11 asthe second pre-alignment shot. The imprint process is executed for eachof shot 11, shot 12, shot 13, and shot 14 in the same manner. Then,every time a new shot region row starts, the pre-alignment measurementis performed by selecting the first pre-alignment shot and the secondpre-alignment shot.

Note that in the example shown in FIG. 5 according to the firstembodiment, shot 74 and shot 77 are defined as PFs. Even for the PF, thearea may be large and it may be possible to ensure the required accuracyof pre-alignment measurement. In this case, for example, as shown inFIG. 10 , shot 74 can be used as the first pre-alignment shot and shot77 can be used as the second pre-alignment shot. When imprinting a rowincluding shot regions from shot 73 to shot 78, there is no FF for whichno imprint process has been performed (because shot 74 and shot 77 aredefined as PFs). However, when shot regions, like shot 74 and shot 77,whose areas are larger than those of shot 73 and shot 76 are used, theaccuracy of pre-alignment measurement can be improved.

This embodiment has explained the case in which pre-alignmentmeasurement is performed for shot 2, and the imprint process isperformed for shot 1, shot 2, and shot 3 in this order. The presentinvention, however, is not limited to this. For example, afterpre-alignment measurement is executed for shot 2, the imprint processmay be executed for shot 2, shot 1, and shot 3 in this order.

Third Embodiment

The third embodiment will describe a pre-alignment shot selectionmethod. As described in the first embodiment, the imprint apparatusindividually measures the positions of the substrate 111 and the mold108 with reference to the apparatus coordinates using the off-axismeasurement device 131 and the TTM measurement device 122. The TTMmeasurement device 122 measures the position of the mold 108 withreference to the position of the TTM measurement device 122 by observingthe mold-side mark 63. On the other hand, the substrate stage 104 thatholds the substrate 111 moves to a position under the off-axismeasurement device 131, and performs global alignment measurement forestimating the position coordinates of all the shot regions on thesubstrate 111 using the off-axis measurement device 131. In the globalalignment measurement, the off-axis measurement device 131 is used tomeasure the marks in the plurality of sample shot regions on thesubstrate 111, thereby measuring the position of each sample shot regionin the substrate 111 with reference to the substrate stage 104. Afterthe global alignment measurement, the above-described pre-alignmentmeasurement is executed for the designated shot region.

FIG. 11 shows an example of this embodiment. In global alignmentmeasurement, a controller 107 drives a substrate stage 104 so as tosequentially send sample shot regions shot 1′ to shot 6′ to themeasurement position (first measurement position) of an off-axismeasurement device 131. After that, the off-axis measurement device 131is used to measure a mark in each sample shot region. At this time, whenthe off-axis measurement device 131 measures shot 6′, shot 6″ is locatednear a measurement position (second measurement position) at which a TTMmeasurement device 122 performs measurement. The controller 107 thusselects shot 6″ as a pre-alignment shot. After the off-axis measurementdevice 131 measures shot 6′, the controller 107 moves shot 6″ selectedas the pre-alignment shot to the measurement position at which the TTMmeasurement device 122 performs measurement. After that, the TTMmeasurement device 122 is used to measure shot 6″ as the pre-alignmentshot. This can shorten the driving distance of the substrate stage,thereby improving the productivity.

<Embodiment of Article Manufacturing Method>

A pattern of a cured material formed by using an imprint apparatus isused permanently for at least some of various articles, or is usedtemporarily when manufacturing various articles. The articles include anelectric circuit element, an optical element, a MEMS, a recordingelement, a sensor, and a mold. Examples of the electric circuit elementare a volatile or nonvolatile semiconductor memory such as a DRAM, anSRAM, a flash memory, or an MRAM and a semiconductor element such as anLSI, a CCD, an image sensor, or an FPGA. An example of the mold is animprinting mold.

The pattern of a cured material is used unchanged as a constituentmember for at least some of the foregoing articles, or is temporarilyused as a resist mask. The resist mask is removed after etching, ionimplantation, or the like is performed in a substrate processing step.

Next, the article manufacturing method will be described. In step SA ofFIG. 12 , a substrate 1 z which is a silicon substrate or the like onwhose surface a processing target material 2 z such as an insulator isformed is prepared, and next, an imprint material 3 z is applied to thesurface of the processing target material 2 z by an ink-jet method. Astate in which the imprint material 3 z in the form of a plurality ofdroplets is applied onto the substrate is shown here.

As shown in step SB of FIG. 12 , a side of an imprinting mold 4 z onwhich its three-dimensional pattern is formed faces the imprint material3 z on the substrate. In step SC of FIG. 12 , the substrate 1 z to whichthe imprint material 3 z has been applied and the mold 4 z are broughtinto contact, and pressure is applied. Gaps between the mold 4 z and theprocessing target material 2 z is filled with the imprint material 3 z.When the imprint material 3 z is irradiated with light as curing energythrough the mold 4 z in this state, the imprint material 3 z is cured.

In step SD of FIG. 12 , when the mold 4 z and the substrate 1 z areseparated after the imprint material 3 z is cured, a pattern of thecured material of the imprint material 3 z is formed on the substrate 1z. The pattern of this cured product has a shape such that the concaveportion of the mold corresponds to the convex portion of the curedproduct, and the convex portion of the mold corresponds to the concaveportion of the cured product; that is, the three-dimensional pattern ofthe mold 4 z is transferred to the imprint material 3 z.

In step SE of FIG. 12 , when the pattern of the cured material is etchedas an etching resistant mask, portions out of the surface of theprocessing target material 2 z where the cured material is not presentor thinly remains are removed, and grooves 5 z are achieved. In step SFof FIG. 12 , when the pattern of the cured material is removed, it ispossible to achieve an article in which the grooves 5 z are formed onthe surface of the processing target material 2 z. The pattern of thecured product is removed here; however, the pattern of the cured productmay be used as, for example, an interlayer dielectric film included inthe semiconductor element or the like, that is, the constituent memberof the article without removing it after processing.

OTHER EMBODIMENTS

Embodiment(s) of the present invention can also be realized by acomputer of a system or apparatus that reads out and executes computerexecutable instructions (e.g., one or more programs) recorded on astorage medium (which may also be referred to more fully as a‘non-transitory computer-readable storage medium’) to perform thefunctions of one or more of the above-described embodiment(s) and/orthat includes one or more circuits (e.g., application specificintegrated circuit (ASIC)) for performing the functions of one or moreof the above-described embodiment(s), and by a method performed by thecomputer of the system or apparatus by, for example, reading out andexecuting the computer executable instructions from the storage mediumto perform the functions of one or more of the above-describedembodiment(s) and/or controlling the one or more circuits to perform thefunctions of one or more of the above-described embodiment(s). Thecomputer may comprise one or more processors (e.g., central processingunit (CPU), micro processing unit (MPU)) and may include a network ofseparate computers or separate processors to read out and execute thecomputer executable instructions. The computer executable instructionsmay be provided to the computer, for example, from a network or thestorage medium. The storage medium may include, for example, one or moreof a hard disk, a random-access memory (RAM), a read only memory (ROM),a storage of distributed computing systems, an optical disk (such as acompact disc (CD), digital versatile disc (DVD), or Blu-ray Disc (BD)™),a flash memory device, a memory card, and the like.

While the present invention has been described with reference toexemplary embodiments, it is to be understood that the invention is notlimited to the disclosed exemplary embodiments. The scope of thefollowing claims is to be accorded the broadest interpretation so as toencompass all such modifications and equivalent structures andfunctions.

This application claims the benefit of Japanese Patent Application No.2020-007017, filed Jan. 20, 2020, which is hereby incorporated byreference herein in its entirety.

What is claimed is:
 1. An imprint method of performing an imprintprocess including a contacting step of bringing a mold into contact withan imprint material supplied onto a substrate, a curing step of curingthe imprint material in a state in which the imprint material and themold are in contact with each other, and a separating step of separatingthe mold from the cured imprint material, the method comprising:acquiring global alignment information including information forspecifying position coordinates of each of a plurality of shot regionsincluding a first shot region and a second shot region of the substrate;performing a pre-alignment measurement including moving, based on theacquired global alignment information, the second shot region to ameasurement position at which a measurement device performs measurement,and measuring a first relative positional shift between the second shotregion and the mold using the measurement device; and moving, based onthe global alignment information and the measured first relativepositional shift, the first shot region to an imprint position at whichthe imprint process is performed, and starting the contacting step.